Brake assembly



v Oct. 27, 1931. J. SNEED 1,829,307

BRAKE ASSEMBLY Original Filed July 24. 1928 .25 26 .1 24 and 24 2O 22 45 :F I611." 10 Go '2 M m n Fer-'6 Patented 6d. 27, 193i UNITED STATES PATENT OFFICE JOHN SNEED, OI FEBNDALE, MICHIGAN, ASBIGHOB TO THE MIDLAND STEEL PRODUCTS COIPANY, O1 CLEVELAND, OHIO, A CORPORATION OF OHIO BRAKE ASSEMBLY Boflllng of abandoned application Serial Io. 295,011, med July 24, 1928. This application filed November 6,

1929. Serial No. 406,023.

This invention relates to brakes and to the spreading mechanism therefor, and particularly to retainers and anti-friction means for the thrust pins of the spreading mechanism.

I choose to illustrate my invention in the environment of a well known brake which is of the internal expanding type and in which the ends of the shoe are spread apart by horizontally disposed toggle mechanism, the ends of which enga e thrust ins which extend axially of the rake an are supported at their ends by spaced inwardly extending arts of the shoe assembly. In applying the brake the pivot point of the togfg e is drawn toward the apron and the end at least one of the thrust pins is necessarily drawn against the apron while moving and sliding along the a ron with its end of the shoe. One of the 0 j ects of my invention is to provide anti-friction means between the ends of the pins and the apron to eliminate wear either of the pin or apron and reduce friction losses.

'Another object is to provide a simple and inexpensive means for retaining the thrust pins in the ends of the shoe and in this re-- spect reference may be had to my copending application Serial No. 286,154, filed June 18th, 1928, wherein I have illustrated and described one form of retainin means.

' Another object is to stan ardize the parts ,including the thrust pins and retaining memhere so that they may be interchangeable y from one shoe to another or from one brake to another. A further object is to arrange and design the arts so that the assembly ma be rapid an eflicient.

ther objects will appear from the following descri tion of a preferred form of my invention, re. erence being had to the accompanying drawings. The essential characteristics are summarized in the claims.

In the drawings, Fig. 1 is a partial elevation of a shoe assembly including the spreading mechanism; Fig. 2 is a section taken along the line 2-2 of Fig. 1; Fi 3 is a section taken along the line 33 of ig. 1; Fig. 4 is a side elevation of a thrust pin; Fig. 5 is a top plan of the same; Figs. 6 and 7 are sections taken along the lines 6-6 and 7-7 respectivel of Fig. 5; and Fig. 8 is a perspective o a retaining member prior to assembly; Fig. 9 is a pers ective of the same member as deformed a ter assembly; Fig. 10 is a side view of one of the antifriction retaining members and Fig. 11 is a top plan view of the same member.

Referring to F i 1, I have illustrated the usual brake drum the open face of which is closed by an apron A. An anchor pin .P is carried by the apron. A shoe S has adjacent ends engagin the anchor pin. One end 1 of the shoe may e pressed from sheet stock into a channel section and the other end 2 which the toggle is flattened. The cable may be drawn by manually operated means not shown. To afford a connection between the ends of the toggle and the ends of the shoe, thrust fpins 10 and 11 are journalled in the ends 0 the shoe and disposed axially of the brake. The thrust pin 10 is j ournalled in the inwardly extending flanges of the channeled end of the shoe and the thrust pin 11 is jounalled in the depending ears 4 of the adjust? inggmember 3.

eferring also to Figs. 4 and 7 inclusive, each of the pins may have flattened horizontal surfaces 12 upon which the ends of the toggle may hear. The pins may have reduced end portions 13 with shoulders 14 adjacent thereto. Referring back to Figs. 2 and 3, the side flanges of the channel have apertures 15 and 16 of equal size and the depending ears of the adjusting members have apertures 17 and 18 of equal size. I prefer that these apertures be equal so that they may be reamed with the same tool. The diameter of the apertures is preferably the same as the greatest diameter of the pins, and it is intended that at least one end of the pins be journalled directly in the apertures. In assembling the pins, the reduced end portions 13 are disposed toward the apron and the full end portions are journalled at least on their 5 arcuate surfaces in the apertures 15 and 17 respectively.

Referring also to Figs. and 11, I provide anti-friction retaining members 20 to overlie the reduced end portions 13 of the 10 pins, and to exte'riorly engage the inner walls of the apertures 16 and 18 respectively. The bottoms of these retaining members frictionally engage the inner face of the apron as at 21. I prefer that these members be made of bronze or like material and have their exterior surfaces impregnated with graphite in a well known manner. These retaining members 20 may be generally cup-shaped but comprise essentially disc like bottoms 22 with 20 pairs of separate upstanding sldes 23 and 24. The upstanding sides 23 may have flattened interior surfaces which bear agalnst the flattened surfaces 12 of the reduced ends of the pins. The upstanding sides 24 may 25 have arcuate internal surfaces engaging the rounding surfaces of the reduced ends of the pins and the upstanding sides 24 may have outwardly flared ears 26, see also Figs. 2 and 3, which engage the inner faces of the flanges of the channel and the inner face of the one of the depending ears 4 of the ad usting member. The inner upper corners of the ears 26 may bear against the shoulders 14 of the pins. I prefer that the members 20 be of l ke size and shape and in instances Where the side flanges of the channel part of the shoe are thinner than the ears 4 of the adJuStmg member, then such means as a washer 30 may be disposed between the ears 26 and the side flange of the channel to shim up the flan e to the same thickness as the -'ear of the ad usting member.

It is to be noted that the depth of the cylindrical walls of the members 20 is greater than the thickness'of the ears 4 of the side flanges of the channeled end of the shoe, so

that the bases of the retaining members extend laterally beyond the sides of the shoe and serve as steady-rests to space the shoe ends from the apron.

The other ends of the pins are retained by U-shaped clips 40, see Figs. 8 and 9 which have spaced upstanding parts lying along the flattened surfaces of the pins and which have cars 41 which are turned back after the clips have been inserted. It will be appreciated that the load on these clips during the operation of the brake is not very great and that relatively pliable or ductile metal may be used.

In operation the spreading force exerted ,by either end of the toggle has a primary circumferential component and a lesser axial component, the pins of course move in their 05 journals when the toggle is expanded and cylindrical surface of the apply the brakes.

also move relative to the apron. The axial component with the spreading force is taken between the retaining members 20 and the apron, and the less the coefiicient friction between these parts the more eiiicient the operation of the brake. As mentioned 'above the retaining members QOmaybe impregnated with graphite so that friction between these members and theapron is reduced-,- to, a minimum. The circumferential componentof the spreadingforce is taken through the retaining members to the Walls of the v aperture in which the pins are journalled. The friction at this'point is also reduced to a minimum to'enhance the operation of the spreading mechanism.

'From the foregoing it will a pear that I have provided means which f assembly of the spreading mechanism; that serve to retain the thrust pins in the ends of the shoe; that reduce the frictionlossw which occur during the spreadingof the ends of the brake shoe, and consequently increase the efliciency at which the brake may be operated and reduce the effort necessary to While I have illustrated and described a preferred form of my in vention, I do not care to be limited in the scope of my patent other than by the claims appended hereto. i l I claim: 1. The combination of a brake shoe, a thrust pin journa-lled in the shoe, and an anti; friction bearing part disposed, between the thrust pin and the shoe.

2. The combination of avbrake shoe having inwardly extending radially spaced flanges; a thrust pin journalled at its ends in said flanges, and an anti-friction bearing part fbr at least one end of said thrust pindispo'sed between said pin and the flange in which the pin is journalled. V I

3. The combination of a brake shoe, an apron, a thrust pin journalled in theshoe and having an end extending toward the apron and a retaining member for theend of I the pin overlying the end of the pin'and en;

gaging said apron to space the shoe' 'away from the apron. i

4. The combination of a brake shoe having inwardly extending radiaIly spaced parts, an apron laterally adjacent the shoe, a thrust pin journalled at its ends insaid parts, and

an anti-friction bearing part for the end of] said thrust pin adjacent the apron disposed.

between said pin and the'flange in whichthe pin is journalled and having an anti-friction part contacting with said apron.

5. The combination of a brake shoe, an apron, a thrust pin journalled in having an end extending toward the apron, and a retaining member overlyingthe end of the pin having an anti-friction surface contacting with said apron and spacing the shoe away from'the apron.

acilitat'e the the shoeand. 5

' means extending toward the apron and generally normal thereto for drawing the pivot point of the toggle toward the apron to expand theshoe, a thrust pin an aged by the toggle and carried bythe end the shoe and disposed generally normal to the apron, and

.a cup shaped member overlying the end of the pin and having an anti-friction exterior base surface slidably engagin the apron.

7. In a brake the combinatlon of a brake shoe,'an apron, a toggle for actuating the shoe, means extending toward the apron and generally normal thereto for drawing vthe pivot point ofthe tog le toward the apron to expand the shoe, a t rust pin en aged by thrust ms.

spaced i rnalled in said apertures having flattened the toggle and carried by the end 0 the shoe and disposed generally normal to the apron, and a separatewear member associated with the end of the thrust pin adjacent the apron for s acing the shoe from the a ron.

8. e gozzilllainaigon of a bra e lslhoe hav in space 'gne apertures, a t ust pin jo rnalled in said apertures having flattened surfaces 'on opposite sides thereof, and retaining members for the ends of the thrust p pins lying at least in' part within said apertures, and retaining, members having U- sha d portions'the egs of-which lie upon and engage the flattened surfaces of said e combination of a brake shoe havaligned apertures,- a thrust pin surfaces on o posite sides thereof and a retaining mem r for one end of'the thrust pins. lying at least in part'within one of said apertures, said retaining member having'U-shaped portions the legs of which lie upon and engage the flattened surfaces of said thrust pin and having anti-friction exteriorsurfaces engaging the walls of said aperture.

10. In a brake, the combination of abrake V shoe having spaced aligned circular openends of the pin ings, a thrust pin journilled in said 0 nings, and retaining members for the en s of the pin having spaced parts extending through said openings and lying along opposite sides of said pin, the inner on s of said parts being flared outwardly at right a les to the pin.

1. In a brake, the combination of a shoe having inwardly extending radial side flanges having aligned circular openings therein, a thrust pin journalled in said openingsand retainin members for the opposite aving parts engaging the and faces of the pin and having parts extendin through said openin and 1 'ng along t e sides of said pin, the mner en s of said last named parts being flared outwardly at right angles to the pin and engaging the inner faces of said flanges.

inwardly extending part with a circular opening therein, a thrust ad least at one end, a U-shaped clip extend ing over the end of the pin with its legs engaging the flattened surfaces thereof, the ends of the legs being turned outwardly after the parts are assembled to engage the side of said inwardly extending part and hold said pin within said opening.

13. A thrust pin retaining member having a disc-like base with separate upstandin side parts. arranged in oppositely dispose pairs, at least one pair of said arts havin outwardly turned ears exten ing parallel with the base and disposed remote therefrom. I

'14. The combination of a thrust pin having flattened surfaces on opposite sldes and a retaining member for one end; thereof having a base portion engaging the end face of the pin and having at least a pair of upstanding side parts having flat interior surfaces enga mg the flattened surfaces of said p n where the member rotates with the 15. The combination of a thrust pin having flattened top and bottom surfaces and a reduced end portion terminating in curved shoulders adjacent the body of the pin, and

' a separate member associated with the re- 12. The combination of a shoe having an in journalled in said opening and having attened surfaces duced end of the pin having a disc like base and pairs of upstanding side parts, one of said pairs of parts engaging the flattened sides of the pin and the other pair of parts havmg curved interior surfaces engaging the curved surfaces of the reduced end port1on and having outwardly turned ears the bases of which engage said shoulders adjacent the body of the in.

In testimony whereo I hereunto afix m signature this 2nd day of November 192 JOHN SNEED. 

